FIG. 1 depicts a portion of conventional head 1 including a conventional perpendicular magnetic recording (PMR) transducer 10 and conventional read transducer 40 separated by an insulator 6, as viewed from the air-bearing surface (ABS). For clarity, the conventional PMR transducer 10 is not drawn to scale. Also depicted is the substrate 2, which may be part of a body of a slider (not separately depicted in FIG. 1). The conventional PMR transducer 10 includes a conventional first pole 12, alumina insulating layer 14, alumina underlayer 16 that may be considered part of the alumina insulating layer 14, conventional PMR pole 18 that typically includes a seed layer (not shown), insulating layer 20, shield gap 26, top shield 28, and insulating layer 30. Note that in certain other embodiments, the top shield 28 may also act as pole during writing using the conventional PMR transducer 10. The conventional PMR pole 18 and the top shield 80 are surrounded by insulating layers 20 and 30, respectively. The conventional PMR pole 18 has sidewalls 22 and 24.
In conventional applications, the height of the conventional PMR pole 18 is typically less than approximately three-tenths micrometer. The conventional PMR pole 18 also has a negative angle such that the top of the conventional PMR pole 18 is wider than the bottom of the conventional PMR pole 18. Stated differently, the angle θ of the sidewalls is less than 90 degrees in the conventional PMR pole 18 of FIG. 1. A pole having this height and shape is desirable for use in PMR applications.
FIG. 2 depicts a conventional method 50 for forming the conventional PMR transducer 10. For simplicity, some steps are omitted. The high magnetic moment material for the conventional PMR pole 18 is deposited, via step 52. A chemical mechanical planarization (CMP) stop layer and hard mask layer are deposited, via step 54. A seed layer is deposited, via step 56. A resist pattern for the hard mask layer is formed on the seed layer, via step 58. Step 58 typically includes providing a layer of photoresist and patterning the layer to provide the desired mask. The ion milling mask is plated and the photoresist removed, via step 60. Thus, the ion milling mask is used to mask the desired portions of the high moment material to be used to form the conventional PMR pole 18. The PMR pole material is milled, via step 62. Consequently, the width of the conventional PMR pole 18 and the negative angle are set in step 62. The insulator 20 is deposited around the conventional PMR pole 18, via step 64. A CMP is performed to planarize the surface and expose the conventional PMR pole 18, via step 66. The surface is planarized in order to allow subsequent processing to be performed as desired. The shield gap 26 is provided, via step 68. The top shield 28 is deposited and patterned in step 70. Finally, the region around the top shield 28 is insulated, via step 72.
Although the conventional method 50 can be used to form a conventional PMR transducer 10, the process utilized to trim the conventional PMR pole 18 results in artifacts which adversely affect the functioning of the conventional PMR transducer 10. In particular, the sidewalls 22 and 24 of the conventional PMR pole 18 may include one or more angles. Such a condition, in which each sidewall 22 and 24 includes an angle, is depicted in FIG. 1. The desired profile of the conventional PMR pole 18 is a trapezoid. Consequently, such nonuniformities in the sidewalls 22 and 24 are undesirable. In addition, footings 23 and 25 may be present at the base of the PMR pole 18. The footings 23 and 25 are composed of the material(s) used in forming the pole. Other artifacts may include increased roughness of the sidewalls 22 and 24 as well as redeposition of the pole material being trimmed. These artifacts of the pole trim are generally undesirable.
Accordingly, what is needed is an improved method for fabricating a PMR head.